VoLiFi as the Next Generation Voice Service over LiFi

The radio frequency (RF) based wireless systems are at fundamental limits due to the exponential growth of mobile data and the increasing need for high quality and low latency voice services. Light Fidelity (LiFi), a high-speed, two-way, and networked optical wireless communication (OWC) system, is a technology utilizing visible and infrared light as its medium and providing many benefits over traditional WiFi and cellular systems, including orders-of-magnitude greater unlicensed spectrum, natural spatial confinement, resistance to RF interference, and greater physical-layer security. In this regard, the idea of Voice over LiFi (VoLiFi) appears to be a promising paradigm that is based on the utilization of LiFi access networks to provide next-generation real-time voice and audio services. Pioneering projects of audio and voice communication over LiFi indicate that it is possible to transmit continuous-time audio streams with satisfactory quality over intensity modulation and direct detection (IM/DD) links. This paper gives a comprehensive system level view of VoLiFi as next generation voice service, its architecture, protocol stack, quality of service (QoS) requirements, the technologies that enabled it, and research challenges. We propose VoLiFi based on the IP-based voice services and hybrid RF-optical networks can offer very secure, low latency, and spectrum efficient voice connectivity to smart buildings, healthcare, industry, and mission-critical systems.